Giant Colombian Ramshorn

Marisa cornuarietis

FreshwaterSnail

Care at a glance

Temperature: 73–81°F (23–27°C)
pH: 6.5–8.0
Adult size: 2 in (5 cm)
Minimum tank: 5 gal (20 L)
Temperament: Peaceful
Social behavior: Solitary
Swim level: Bottom
Difficulty: Easy
Breeding: Medium
Rarity: Common
Origin: Central America, South America
Family: Ampullariidae

Overview

This is a peaceful, mostly solitary bottom grazer that spends its time working over surfaces for algae and decaying plant matter. Be warned: it readily eats live aquarium plants, so it suits an algae-control or low-plant tank rather than a planted display. Feed it algae wafers, blanched vegetables, and leftover food. Keep the water warm and on the harder side, and avoid copper-based treatments, which are toxic to snails.

In the wild

The giant Colombian ramshorn lives in warm, calm waters across Central and South America, from ponds and ditches to slow rivers full of plants. It crawls over surfaces grazing on algae and soft vegetation. A tank from about 20 liters works, with warm water in the mid 20s C and pH from 6.5 to 8. Harder water with some mineral content helps keep its shell solid, since soft acidic water can pit and erode it.

Good to know

Marisa cornuarietis is an apple snail in the family Ampullariidae, reaching about 5 cm across its flat, coiled shell. Unlike many pond snails it has separate sexes rather than being a hermaphrodite, so you need a male and a female to breed. It lays gelatinous egg masses under the water surface, not above it like some of its relatives. Breeding is moderate to manage given the right conditions.

Did you know

This snail has been used as a biological control agent against pest snails and weeds in some regions, because it eats vegetation and competing snails so eagerly. That same appetite is exactly why it has become an invasive problem where it escaped, and why you should never release one into local waters.